1. Field
This application relates generally to the field of machine vision, and more specifically to a machine-vision system for remotely monitoring the quality of a product.
2. Description of Related Art
Quality inspection is a critical element of modern industrial automation systems. Typically, a quality inspection system involves the inspection and measurement of critical aspects of a product. Traditionally, a quality engineer or technician inspects a sample quantity of products in a production run and takes one or more measurements to determine a quality metric. If the quality metric satisfies a set of quality criteria, the production run is typically approved for shipment or sale. The effectiveness of the quality inspection system depends, in part, on the number of inspections that can be performed, the accuracy of the measurements taken, and skill of the quality engineer or technician.
In an effort to improve the effectiveness of a quality inspection system, machine vision can be used to monitor multiple inspection points using digital cameras placed throughout the manufacturing process. Machine vision may improve the reliability of a quality inspection system by increasing the number of inspections that can occur, providing precise measurements, and reducing the potential for human error.
In a typical machine-vision system, a digital image or video of a product may be acquired using a digital camera or sensor system. By analyzing the digital image or video, measurements for key features may be obtained and the product can be inspected for defects. A machine-vision system typically includes an image acquisition device (e.g., camera, scanner, or sensor) and a local processor for analyzing acquired digital images.
To monitor the quality of a product, multiple machine-vision systems are typically distributed throughout a production line or even across multiple production lines in different production facilities. Traditionally, each machine-vision system operates as an individual, autonomous cell in a production line and may only control a single aspect of the manufacturing process. That is, the output of a traditional machine-vision system may only provide binary output (pass/fail) in order to control an associated portion of the manufacturing process.
This autonomous-cell approach to machine vision has significant limitations. For example, using this approach, it may be difficult for a quality engineer or technician to monitor multiple machine-vision systems or to aggregate data from multiple inspection stations. Furthermore, current systems do not support remote access and control and may require that the quality engineer or technician be physically located near the inspection station to monitor or maintain the inspection operations. Thus, the configuration of each inspection station may not be easily updated resulting in non-uniformity across systems, making revision control difficult.
An additional drawback of current, autonomous-cell machine-vision is that it does not support cross-camera data sharing. Many facilities have multiple inspection stations located along a production line (or in multiple facilities), but the stations can only function as independent units—they are not capable of sharing data. The ability to share data may be especially important for complex manufacturing processes because it allows a more holistic approach to quality inspection.
Traditional autonomous-cell machine-vision systems have not been integrated as part of a more comprehensive quality inspection system due to significant technical challenges. For example, a typical machine-vision system using a high-resolution digital camera acquires and analyzes an immense amount of image data that may not be easily communicated or stored using traditional systems or techniques. Additionally, current automation systems do not readily provide for external access to or remote control of individual inspection stations.
The system and techniques described herein can be used to implement a machine-vision system for remote quality inspection of a product or system without many of the limitations of traditional systems discussed above.